After you configure a NAS mount point for a Function Compute service, you can write code to access files in the NAS just like accessing a local file system. This topic provides an example of the function code for writing and reading NAS files.

Create a function to write to a NAS file

  1. Log on to the Function Compute console.
  2. In the left-side navigation pane, click Services and Functions.
  3. In the top navigation bar, select the region where the service resides.
  4. On the Services page, find the service that you want to manage and click Functions in the Actions column.
  5. On the Functions page, click the name of the function that you want to manage.
  6. On the function details page, click the Function Code tab and write code in the code editor.
    In this topic, Python 3 is used as an example. The following sample code is used. 
    #!/usr/bin/env python
# -*- coding: utf-8 -*-

import random
import subprocess
import string
import os

def handler(event, context):
  # report file system disk space usage and check NAS mount target
  out, err = subprocess.Popen(['df','-h'], stdout = subprocess.PIPE).communicate()
  print('disk: ' + str(out))
  lines = [ l.decode() for l in out.splitlines() if str(l).find(':') != -1 ]
  nas_dirs = [ x.split()[-1] for x in lines ]
  print('uid : ' + str(os.geteuid()))
  print('gid : ' + str(os.getgid()))
  for nas_dir in nas_dirs:
    sub_dir = randomString(16)
    file_name = randomString(6)+'.txt'
    new_dir = nas_dir + '/' + sub_dir + '/'
    print('test file: ' + new_dir + file_name)
    content = "NAS here I come"
    os.mkdir(new_dir)
    fw = open(new_dir + file_name, "w+")
    fw.write(content)
    fw.close()
    # Showing the folder tree in NAS
    for root, dirs, files in os.walk(nas_dir):
      level = root.replace(nas_dir, '').count(os.sep)
      indent = ' ' * 2 * (level)
      print('{}{}/'.format(indent, os.path.basename(root)))
      subindent = ' ' * 2 * (level + 1)
      for f in files:
        print('{}{}'.format(subindent, f))
  return 'success'

def randomString(n):
  return ''.join(random.SystemRandom().choice(string.ascii_uppercase + string.digits) for _ in range(n))

Create a function to read NAS files

  1. Log on to the Function Compute console.
  2. In the left-side navigation pane, click Services and Functions.
  3. In the top navigation bar, select the region where the service resides.
  4. On the Services page, find the service that you want to manage and click Functions in the Actions column.
  5. On the Functions page, click the name of the function that you want to manage.
  6. On the function details page, click the Function Code tab and write code in the code editor.
    In this topic, Python 3 is used as an example. The following sample code is used. 
    # -*- coding: utf-8 -*-

def handler(event, context):

    f = open("/mnt/test/test.txt", "r")

    print(f.readline())
    f.close()
    return 'ok'
    The execution result of this function is what is written through the Create a function to write to a NAS file.